This invention relates to stereo imaging systems, devices, and methods. In particular, the invention relates to a method of imaging a target site with a stereo imaging system, a method of aligning images of a stereo imaging system, a method of adjusting the stereo working distance of a stereo imaging system, and a stereo imaging system.
In minimally invasive surgery such as laparoscopic surgery, for example, a patient""s abdomen is insufflated with gas, and trocar sleeves or cannulas are passed through small incisions to provide entry ports for laparoscopic surgical instruments. The laparoscopic surgical instruments generally include an endoscope in the form of a laparoscope for viewing the surgical site or field and surgical instruments defining end effectors such as clamps, graspers, scissors, staplers, and needle holders. The surgical instruments are similar to those used in conventional (open) surgery, except that the working end of each tool is separated from its handle by an elongate shaft. To perform surgical procedures, the surgeon passes instruments through the trocar sleeves and manipulates them from outside the abdomen by sliding them in and out through the sleeves in the abdominal wall, and actuating end effectors on distal ends of the instruments, while viewing the surgical site through the laparoscope.
In robotically-assisted and telerobotic surgery (both open and endoscopic procedures), the position of the surgical instruments is typically controlled by servo motors rather than directly by hand. The servo motors follow the motions of a surgeon""s hands as he or she manipulates input or master control devices whilst remotely viewing the operation via an image displayed on a viewer, the viewer being operatively linked to an image capture device typically in the form of an endoscope. The viewer and its associated image capture device form part of an imaging system. The servo motors are typically part of an electromechanical surgical apparatus, which typically includes robotic arms that support and control the surgical instruments that have been introduced into e.g. an open surgical site, or through trocar sleeves into a body cavity, such as the patient""s abdomen, or the like. During the operation, the master control devices provide mechanical actuation and control of a variety of surgical instruments. Such surgical instruments can typically include tissue graspers, needle drivers, etc., that can perform various surgical procedures for the surgeon, i.e., holding or driving a needle, grasping a blood vessel, dissecting tissue, and the like, while the surgeon views the procedures on the viewer.
It will be appreciated that the imaging system should meet certain criteria to render it suitable for use in applications such as minimally invasive surgical applications. In particular, the image displayed to the surgeon should be clear and optically correct. Furthermore, the imaging system should provide an adequate field of view and adequate resolution and brightness, so as to enable the surgical field to be adequately visualized by the surgeon.
Stereo endoscopes are sometimes used to provide the surgeon with a stereo image at the viewer. Stereo endoscopes are typically arranged to have a fixed point of intersection between two viewing axes. The distance between the fixed point and an object viewing end of the endoscope is referred to as the xe2x80x9cworking distancexe2x80x9d of the endoscope. In use, the surgeon, whilst performing a surgical procedure, may want to observe an object removed from the point of intersection. For example, when using the endoscope to xe2x80x9csearchxe2x80x9d for the surgical site, the surgeon typically observes objects at a working distance beyond the point of intersection. When the surgical site is reached, he or she may want to observe objects which are closer to the viewing end of the endoscope or beyond the point of intersection when the surgical procedure is actually performed.
Additionally, stereo endoscopes are not always precisely optically aligned due to, e.g., manufacturing constraints, and the like. In other words, the viewing axes sometimes do not intersect either precisely or at all. When such an endoscope is used, without compensating for such misalignment of the viewing axes, it could lead to the surgeon experiencing premature eye strain, headache, and/or general fatigue in attempting to compensate for the imprecise xe2x80x9cstereo imagexe2x80x9d. Compensating for such misalignment should increase the time between when a surgeon commences a surgical procedure and when he or she becomes tired and thus less efficient at performing the procedure. Accordingly, it should enhance the overall comfort of the surgeon, enabling the surgical procedure to be performed in a more precise manner, by enhancing the optical comfort experienced by the surgeon during a surgical procedure.
It is an object of this invention to provide an imaging system which provides for adjustment of the working distance of a stereo endoscope. It is also an object of this invention to provide an imaging system which provides for alignment of the viewing axes of such a stereo endoscope. Further objects will be apparent from the following description of the preferred embodiments of the invention.
According to one preferred aspect of the invention, there is provided a method of imaging a target site with a stereo imaging system. The method comprises capturing a right and a left optical image of the target site. It further includes transforming the right and the left optical images into regulatable information, converting the regulatable information into opposed images of the target site displayed in a stereo display of the stereo imaging system, one of the opposed images being associated with the right optical image and the other of the opposed images being associated with the left optical image, and regulating the regulatable information to cause the position of the target site displayed on the opposed images to change relative to each other.
According to another preferred aspect of the invention, there is provided a method of aligning opposed images of a stereo imaging system. The method comprises capturing a right and a left optical image of a target site, transforming the right and the left optical images into digital information in the form of digital arrays associated with each of the right and the left optical images, converting the digital information associated with each digital array into opposed images of the target site displayed on a stereo display of the stereo imaging system, and isolating a portion of at least one digital array so that only digital information associated with the isolated portion of that array is converted into an associated image, the isolated portion being selected so as to align the opposed images displayed on the stereo display.
According to yet another preferred aspect of the invention, there is provided a method of adjusting the stereo working distance of a stereo imaging system.
The method comprises capturing a right and a left optical image of a target site, transforming the right and the left optical images into digital information in the form of digital arrays associated with each of the right and the left optical images, converting the digital information associated with each digital array into opposed images of the target site displayed on a stereo display of the stereo imaging system, and isolating a portion of at least one digital array so that only digital information associated with the isolated portion of that array is converted into an associated image, the isolated portion being selected to cause the working distance to vary.
According to yet a further preferred aspect of the invention, there is provided a stereo imaging system comprising a stereo image capture device for capturing a right and a left optical image of a target site. The system further includes an image transformer operatively associated with the image capture device for transforming the right and the left optical images into corresponding regulatable information, two display areas operatively associated with the image transformer for displaying a right and a left image derived from the corresponding regulatable information, and a processor arranged to regulate the regulatable information to cause the positions of the target site displayed on the opposed images to change relative to each other.
Advantageously, the regulatable information is in the form of digital information.
According to yet a further preferred aspect of the invention, there is provided a method of imaging a target site with a stereo imaging system. The method comprises capturing first and second optical images of the target site as regulatable information, the first and second optical images defining a positional relationship, manipulating the regulatable information to define an altered positional relationship, and converting the manipulated regulatable information into left and right images of the target site and displaying the left and right images on a stereo display of the stereo imaging system.
According to yet another preferred aspect of the invention, there is provided a method of aligning opposed images of a stereo imaging system. The method comprises capturing a right and a left optical image of a target site, transforming the right and the left optical images into regulatable information associated with each of the right and left optical images, converting the regulatable information into images of the target site displayed on a stereo display of the stereo imaging system, and regulating the regulatable information to align the images displayed on the stereo display.
According to yet another preferred aspect of the invention, there is provided a method of adjusting the stereo working distance of a stereo imaging system. The method comprises capturing a right and a left optical image of a target site, transforming the right and the left optical images into regulatable information associated with each of the right and the left optical images, converting the regulatable information into images of the target site displayed on a stereo display of the stereo imaging system, and regulating the regulatable information to adjust the stereo working distance of the stereo imaging system.
According to yet another preferred aspect of the invention, there is provided a method of producing a stereo image of a site at a predetermined position, the method comprising aiming a viewing end of a stereo endoscope at the site so that the first image of the site is passed along a first optical path of the stereo endoscope and a second image of the site is passed along another optical path of the stereo endoscope. The method further comprises converting said first and second images into corresponding first and second sets of electronically readable information, causing the first set of electronically readable information to be transferred into a first visual image on a first display area, causing the second set of electronically readable information to be transferred into a second visual image on a second display area, and directing the images from the display areas to the predetermined position so that, at the predetermined position, the images together form a stereo image viewable by an operator.